- Have started, stopped, or changed doses, within 30 days before study entry, of certain drugs including: benzodiazepines, except midazolam and triazolam; bupropion; calcium channel blockers, except diltiazem and verapamil; fluconazole; lipid-lowering drugs except pravastatin (i.e., atorvastatin, cerivastatin, and fluvastatin, but not lovastatin and simvastatin); isoniazid; mexiletine; zaleplon; and zolpidem. The patient can, however, remain on stable doses of these drugs during the study.